Drive mechanism for crossing protective systems or the like



May 6, 1941.` J. M.' EVANS 2,240,948 DRIVE MECHANISM FOR CROSSING PROTECTVE SYSTEMS OR THE LIKE Filed Nov. 9, 1936 5 Sheets-Sheet l May 6, 1941., J. M. EVANS DRIVE MECHANISM FOR CROSSING PROTECTIVE SYSTEMS OR THE LIKE Filed Nov. 9, 1936 5Sheets-Sheet 2 #5 INVENTOR.

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' ATQTORNYS,

May 5 1941 J. M. EvANs 2,240,948

DRIVE MECHANISM FOR CROSSING PROTECTIVE SYSTEMS OR THE LIKE Filed Nov. 9, 1936 5 Sheets-Sheet 3 lNVE/vToR. 7227/65 7, 744275.

fwd' x A TTOR NEYS.

May 6 1941- J. M. rivANsv '2,240,948 DRIVE MECHANISM FOR CROSSING PROTECTIVE SYSTEMS OR THE LIKE Filed Nov. 9,1936 5 sheets-sheet 4' of: return stroke.

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I N VEN TOR.

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May v6, 1941- J. M. EVANS 2,240,948

DRIVE MECHANISM FOR CROSSING PROTECTIVE SYSTEMS OR THE LIKE Filed'Nov. 9, 1936 5 `Sheecs--Sheet 5 /sPZ l v 7,; 1.9;

a l f; u /f5'7 l( L l l l [9? 71] o oIO o Wfl 7957/ /XH I fl] Supply auf INVENTOR. .1 5. 7142765 M1/4775.

Patented May 6, ISM

UNETED STATES PATENT Ghi DRIVE, MECHANESMI FOR CROSSING PRO- TECTVE SYSTEMS R THE LIKE 9 Claims.

The present invention relates to drive units and control systems therefor, and in particular provides an improved driving unit and control system for a barrier type protective system.

The co-pending applications of the present applicant, Serial No. 108,149, led October 29, 1936, now Patent No. 2,164,410, issued July 4, i939, and of William G. Miller, Serial No. 125,081, led February l0, 1937, now Patent No. 2,178,880, issued Nov. 7, 1939, both assigned tothe assignee of the present application, disclose and claim certain features of an improved crossing protective system of the barrier type, that is, a system embodying a plurality of retractable and projectable barriers, imbedded in a highway at opposite sides of a railway crossing or other intersection. In the preferred use of the barriers, the approach to the crossing of, for example, a train, causes each of the barriers at the particular intersection to start upwardly. The upward motion is interrupted at an intermediate stage for a predetermined interval, and then is continued until the barriers reach a maximum elevated position. The departure of the train or other actuating vehicle from the intersection automatically causes the barriers to again move to the retracted position.

Specifically, the present invention is directed to the provision of an improved driving unit and control system therefor, responsive to the approach and departure of a train or other vehicle to and from a railway block or section associated with a crossing, for the protective device of the above identiiied co-pending application of the present applicant. It will be appreciated, however, from a complete understanding of the present invention that the drive unit thereof is applicable to uses other than the just specified use and may be used with signals and barriers of constructions other than the particular construction disclosed in the above identied co-pending application. Similarly, the improved control system of the present invention may be embodied in protective and other systems differing from the particular embodiments thereof shown herein. The description and illustration of the present invention, in conjunction with a particular type of barrier system, is, therefore, to be regarded in an illustrative and not in a limiting sense.

With the foregoing considerations in mind, an object of the present invention is to provide an improved motor driven drive unit for a barrier device or a similar reciprocable or otherwise intermittently operable element, which is simple in construction, embodies relatively few operating parts,

and which may be economically manufactured, assembled and maintained.

Further objects of the present invention are to provide an improved drive vunit embodying a motor element and a iiywheel element connected thereto and adapted to be interposed between the motor element and the load to absorb shocks; to provide such a drive unit embodying servo mechanism driven by the motor for controlling the operation of the motor; and to provide such a drive unit embodying a brake associated therewith and selectively actuable in connection with the motor unit, so that the drive unit may be selectively released or operation or selectively locked in a predetermined rotative position.

Further objects of the present invention are to provide a drive unit, as above generally stated, embodying an improved releasable clutch connection between the motor and an operating shaft of the drive unit; and to provide such a unit embodying selectively releasable ratchet mechanism for locking the drive unit in a predetermined operating position.

Further objects of the present invention are to provide an electrical controller for use in a drive unit of the above stated character or the like, einbodying a rotatable shaft and a plurality of contact actuating cams mounted thereon; and to provide such a controller embodying a plurality of adjustably positioned moving contacts, disposed to be actuated by the controller cams, between contact closing and contact opening positions.

Further objects of the present invention are to provide an improved control system for a drive unit of the above stated character, including switching mechanism responsive to a predetermined operating condition for starting the motor element of the drive unit, in combination with means including the electrical controller for bringing the motor to rest after a predetermined period of travel and for retaining it at rest for a predetermined interval; to provide such a system in which the motor unit is automatically again set in operation at the expiration of the predetermined interval, and is again brought to rest after an additional predetermined period of travel; to provide such a system in which, in response to a second predetermined operating condition, the motor unit is again placed in operation and rotates continuously until the drive unit is in the original operating position; and to provide such a system in which means, including the electrical controller, are provided to insure the just stated operating cycle even in the event of variations in the just stated predetermined operating condition.

With the above and other objects in view, which appear in the following description and in the appended claims, a preferred but illustrative enibodiment of the present invention is shown in the accompanying drawings, throughout which cor responding reference characters are used to desig nate corresponding parts, and in which:

Figures 1 and 2, taken together, with Fig. 2 confsidered as positioned to the right of Fig. 1, comprise a perspective View of the improved drive unit of the present invention shown as connected for operating a highway protective device;

Fig; 2A is a schematic view, illustrating the preferred arrangement of barriers adjacent a crossing;

Fig. 3 is a top plan view of the improved drive unit;

Fig. 4 is a View in elevation, taken along the line 4-4 of Fig. 3;

Fig. 5 is a view in end elevation, taken along the line 5--5 of Fig. 4;

Fig. 6 is a detail View of ratchet locking strucu ture, taken along the line 6 6 of Fig. 4.;

Fig. 7 is a view in central lo-ngitudinal section of the drum type electrical controller of the present invention;

Fig. 8 is a View in vertical transverse section, taken along the line 8-8 of Fig. 7;

Figs. 9, 10, 11, 12 and 13 are detail views of the cam and contact structures utilized in the electrical controller of Fig. 7 and showing the angular relation of the contact actuating cams;

Figs. 14 and 15 are diagrammatic views, illustrating the mechanical operating relation between certain of the coils and the contacts controlled thereby, of relay structures utilized in the invention, which contacts and coils are shown in spaced relation in Fig. 17;

Fig. 16 is a schematic diagram of a preferred track control system for initiating the operation of the drive unit;

Fig. 17 is a schematic diagram of a preferred control system for the drive unit, disposed to respond to the control system of Fig. 16; and

Fig. 18 is a schematic diagram of a preferred circuit for supplying electric power to a track system with which the drive unit of the present invention may be associated.

Referring first to Figs. 1, 2 and 2A, the illustrated barrier device comprises an elongated shell-like member 2D, generally triangular in transverse vertical section, which is pivotally connected at a rear corner to the rear wall of an associated casing 22. Barrier 2d is illustrated as in the projected position, in which the generally arcuately formed front face thereof presents an impact surface in the path of oncoming vehicles, and which is suiciently high and properly inclined to bring the vehicle to rest.

As best shown in Fig. 2A, a complete installation of the devices preferably comprises four ban riers 20 for each intersection, two thereof being disposed in end to end relation at one side of the railway crossing and the other two being disposed at the other side. One device 20 at each side is associated with the oncoming traffic lane, and the other device at the same side is associated with the outgoing traiiic lane. As described in the above identified co-pending application Serial No. 108,149, it is preferred to provide each barrier associated with an oncoming lane with means to 'positively lock or hold it in the projected position upon its arrival at such projected position. It is preferred, however to enable vehicles otherwise entrapped between the barriers to pass over and depress a barrier associated with an outgoing lane. Accordingly, the oncoming and outgoing lanes at each side of the intersection are provided with barriers individual thereto. The casings 22 are suitably embedded within the roadway surface in such position that when the associated barriers are in the retracted position, the enclosed upper surfaces thereof lie substantially flush with the roadway, and thus form a continuation thereof.

Preferably and as illustrated, one drive unit, designated as' a whole as 24, is provided for each side of the intersection, and each such drive unit is common to both of the barriers at that side.

Each barrier 2Q is provided with a crank shaft 26, which extends longitudinally therethrough, and the offsets in which are connected to the barrier by retracting arms 28, each of which preferably embodies a resilient element. Each connection between a retracting arm 28 and the associated crank shaft is of the lost motion type, so arranged that a rotation of the crank shaft in either direction from the illustrated position through an angle of approximately 180 forcibly pulls the barrier to the retracted position, against the force of the lifting torsional springs 30 associated therewith. During rotation of the crank shaft from such opposite position to the illustrated position, the barrier is caused to rise under the influence of the torsional springs 3U, one end of each of which is connected to 'the casing 22 and the other end of each of which is connected to the barrier through resilient arms 32. The rate at which the barrier rises under the iniuence of the springs 30 is controlled by the rate of rotation of the crank shaft 26. In View of the lost motion connection between the arms 28 and the crank shaft 26, it will be appreciated that while the crank shaft is effective to control the rate of rise of the barrier, it is ineffective to apply a lifting force to the barrier. Accordingly, the barrier may be forcibly pushed down or depressed against the force of the torsion springs Si) independently of the rotative position of the crank shaft. It will also be appreciated that a complete barrier operating cycle, including a movement from the normal retracted position to the illustrated projected position, and a return movement thereof to the retracted position, may

be effected during a single complete revolution of the crank shaft 26.

A resilient coupling 33, which may be of conventional construction and hence has not been illustrated in detail, is preferably provided to form a connection between the shaft of the drive unit and the crank shaft 2S of the adjacent barrier 2B. A similar flexible coupling may be provided to form a connection between the other end of the crank shaft 26 and the crank shaft of the immediately adjacent barrier.

As shown generally in Fig. 1, and in greater detail in Figs. 3, 4, 5 and 6, the drive unit 24 comprises a combined motor, brake and reduction gear unit lil which is connected through a sprocket chain 42 to the sprocket associated with a combined fly-wheel and sprocket 44. The latter element is drivingly connected to the main drive shaft i6 with which coupling 33 is associated, and also drives an electrical drum type controller 4B through a sprocket chain 50.

The drive unit is housed in a casing framed by angle members 5I and 52 and enclosed by walls 54. The top of the casing is enclosed by a removable cover 56, the locking chain 51 of which maybe `released by lifting the cover 52 of an adjacent'manhole; The casings may be suitably securedtothe end ofthe associated barrier casing 22with:L theftop thereof substantially flush With the top of the casing 22v and with the drive shaft 46 thereof substantially axially aligned withV the `crankshaft 2B associated with the barrier.

The combined motor, reduction gear and brake is a commerciallyavailable article and the construction -in-:detail thereof forming no part of the present invention, has not been illustrated in detail. Itis sufficient for the present description to note that the shaft of the motor element, whichv may be constructed to utilize either direct current or alternating current, is connected through'suitablespeed reducing gears to a shaft lil'iwhich extends externally of the motor housing. A conventional spring applied electromagnetically released brake is secured to the motor shaft within the housing. The internal connections'forthe'fmotor unit are such that completion 'of the motor armature circuit also completes the circuit for the electromagnets provided to release the brake. Each starting operation thus simultaneously completes the motor power circuit andalso releases the brake. Each stoppingy operation simultaneously interrupts the motor power circuits Yand also interrupts the brake circuit, bringing'the' motor to rest with the brake applied. The support for the motor unit 4|) is provided by a pair of angle members 62 which yextend between the side walls of the associated casing and are suitably supported upon the angle brackets which dene the casing. The base 64. of unit MJ is secured to angle brackets 62" by a plurality of studs 56,

The-drive shaft '46 is rotatably journaled in a pair of pillow blocks 'i0 which in turn are supported within the casing on transversely extend ing angle members l2, the opposite ends of which are secured to the opposite walls of the casing as by brackets 'M2' The ends 'It of drive shaft 46 are each of reduced section to accommodate the hub of a flexn'ble coupling such as the previously mentioned-coupling 33, and each end extends to a point closelyadjacent the associated end of the drive unit casing. With thisr arrangement, either end of the shaft li'may be coupled to the crank shaft of an associated barrier, or, stated in another waypa drive unit may be connected at either'- end of an associated barrier.

The combined ily-wheel and sprocket member 44; which is drivingly connected to shaft 46 through a key Sil, preferably comprises a hub 82 having'an annulus 86, a pair of similar oppositely l disposed relatively heavy fly-wheel members 86, and a ring-likeV sprocket member 88. rihe flywheel -members, which are secured together by a plurality of circumferentially arranged studs 89, retain the sprocket member B3 between them and, as 'will be evident, are fixed in place axially of the vhub 82 tby the `annulus S4. As will be appreciated, the riy-wheel effect of member 44 absorbs any'operating shocks transmitted from the barrier to the drive unit and prevents such shocks from unduly loading the motor unit fi,

In order to provide for manual operation of the barrier, inthe course of maintenance or inspection worln'the shaft d6 is provided with a ratchet wheel Qil'xed thereto by a key 92, the periphery of which is adapted to receive a usual spannerwrench or other tool, and also to cooperatewith a locking dog 94. Dog 94 is pivotally ymounted upon a transversely extending channel meinberlin? by means of a pin a8.' The nose VIii-tl of doggd'is disposed in axially offset relation `to Vthe main? body portion |02 thereof and an extension |04 is disposed in oppositely axially offset relation to the body portion |02. The projection It@ rests upon a supporting member |86 to prevent rotation of the dog in a clockwise direction from the position illustrated in Fig. 6. The dog normally occupies a position angularly displaced from that shown, with the projection- |84 resting upon the base |81 of the supporting member, in which position the nose i's freeiofthe ratchet 9U.

In'orderI to release the shaft d6' from the effect of the brake associated with the motor unit 40 in the eventi of manual operation, lthe motor drive pinion l is connected to the shaft of the motor drive unitby a releasable clutch. In the form illustrated, a clutch body ||2 is splined or -keyed to the shaft (t0-and is provided with axially projecting diametrically opposed fingers ilifadapted to be received in slots formed in the hub H6 of the drive pinion, which pinion is freely'rotatable upon the shaft Sil. A stud ||8 is threaded yinto anaxially extending passage in shaft B and serves t0 retain the clutch body in assembled relation to the pinion. By backing oif stud IIS, clutch body ||2 may be moved axially of shaft ii!) tothe right, as viewed in Fig. 4, rotracting the fingers lill from the associated slotsin the pinion; .'I'hus, disengaged from the clutch body, the pinion i2 may be freely rotated relative to-shaft 60.5

For manual operation the just described clutch is released, rendering the previously mentioned torsion springs effective to raise the associated barriers to the full height. This raising movement mayfinvolve rotation of shaft 46 in either direction since, as previously stated, the barrier' crank shafts occupy substantially dead center positions when the barriers are retracted. To' manually lower a barrier, the dog 94 may be rotatedto the'illustrated position, and the shaft li may thenbe rotated in step by step fashion by applying-a Spanner wrench to the ratchet wheel ln each such ratchet position,` dog 94 is effective to retain shaft 13S against rotation under the influence of the torsion springs.

Referring particularly to Figs. 7 t0 13, inclusive, the controller |18' comprises generally a cupshaped base member |29 upon which the contact carrying structure 22 is supported by a plurality of studs |241.J The base |20 is flanged and is se cured by studs |2| `to an upright member |23 carried uponrmember i2 (Fig. 5). The Contact carrying structure |22 includes an upper longitudinally extending baror arm |26 and a similar lower bar or armi|23, which arms are connected together adjacent the left-hand ends thereof, as viewed in Fig. 7, by a cross-member |i and are connected together at the right-hand end thereof by a three legged bracket |32, each leg of which is provided with an elongated opening |34 for cooperation with an associated supporting stud |24." As will be appreciated, the elongated openings |34 permit the contact carrying structure |22 to be bodily rotated through a limited angle relative to the base |23 and also relative to the controller shaft |36 to thereby adjust the rotative positions of the latter at which the various contacts are opened and closed.

The upper arms |25 carries ve stationary contact strips |40, hi?, |44, |66 and |48A electrically insulated from the arm |26 by a' block of insulating material |56 secured to arm I 26 by The contact strips are securedto arm |26 by studs, such as |54 (Fig. 8), which carry the usual terminal nuts, such as |56. The lower arm |28 is provided with a corresponding series of movable contacts |60, |62, |64, |66 and |68, each of which is formed of flexible, electrically conducting material and which are insulated from the arm |28 by a strip of insulating material |10. The movable contacts |60, |62, |64 and |66 are connected together for reasons explained hereinafter by a jumper |12. The stationary contacts |40 and |42 are similarly connected together by a jumper |14. A terminal stud, such as |16, is associated with each moving contact, as clearly appears in Fig. 8. For purposes of convenience, the pairs of contacts |40--|60, |42-|62, |44|64, |46--I66 and I48--I68 are designated CI, C2, C3, C4 and C5, respectively.

The controller drive shaft |36 is journaled in a bearing |80 provided therefor in the previously mentioned cross-member |38 and a second bearing provided therefor by the hub |82 of the contact carrying member |22. The cross-member |30 also serves to support the studs |84 by which the enclosing casing |86 is secured to the base member |20. The axially projecting end of the shaft |36 is provided with a sprocket wheel |88 keyed thereto by a key |80 (Fig. 3). Sprocket |88 is driven by the previously mentioned chain 5I) which passes around a similar sprocket |92 secured upon the drive shaft 46. The driving relation is illustrated as one in which a complete revolution of the drive shaft 46 results in a corresponding complete revolution of the controller shaft |36.

The controller shaft |36 carries a plurality of contact actuating cams |8I, |83, |85, |81 and |89, each of which is suitably keyed thereto and each of which is disposed to permit its associated movable contact to remain closed throughout a predetermined portion of a complete revolution of the drum controller and to cam such contact to an open position during movement of the drum controller throughout the balance of a complete revolution.

The various contact pairs CI through C5 are shown in the positions occupied thereby when the barrier is at rest in the retracted position and legends are applied adjacent these figures to identify the parts of the barrier travel during which the respective contacts are closed or opened. It will be appreciated that the figures given in the legends are illustrative and may, in practice, Vary considerably. It may be noted that the four inch level appearing in the legend represents the intermediate hesitation or stopping point, and that the nine and one-half inch level represents the fully projected position. Referring to the legends underneath Figs. 9 to 13, contact CI is open at all times except when, during an elevating movement, the barrier elevation is between one-half inch and four inches. Contact C2 is open throughout each entire elevating movement but is closed when the barrier reaches its maximum elevated position (91/2 inches) and remains closed until the retracted position is reached. Contact C3 is open at all times except when, during an elevating movement, the barrier elevation is between four inches and nine and one-half inches, the maximum elevated position. Contact C4 is normally closed but opens when, during an elevating movement, the barrier elevation reaches four inches and remains open until the barrier passes the maximum elevated position and, in its downward movement, reaches an elevation of nine aardgas inches, or slightly below the maximum elevated position. The iinal contact C5 is open at all times except when, during an elevating movement, the barrier elevation is between one-half inch and nine and one-half inches, the maximum elevated position.

A conduit ISI is provided for introducing conductors into the controller 48. A similar conduit |93, provided with terminal boxes |95, extends between the ends of the drive unit casing and serves to carry the conductors which connect the drive unit and the barrier to the external source of supply.

Track and drive unit control systems The electrical control system for the barrier is shown in the control diagrams of Figs, 16, 17 and 18. The control system comprises generally a system of track circuits (Fig. 16), a system of circuits including the just described electrical controller, responsive to the track circuits (Fig. 17) and a preferred arrangement of power supply circuits (Fig. 18).

Referring rst to Fig. 16, four barriers 20 are shown associated with a railroad crossing and arranged in the manner described with reference to Fig. 2A. The two barriers 20 at one side of the crossing are provided with a drive unit 24 and the two barriers at the other side of the crossing are provided with a similar drive unit 24A. The two parallel railway tracks are designated generally as TI and T2, and it may be assumed that the tracks are used by trains traveling in the direction indicated by the arrows. In accordance with conventional practice, the rails of track TI are provided with blocks of insulation |91 which divide the track into a signaling block which extends from a substantial distance in advance of the crossing in the direction of train travel to a distance slightly beyond the crossing. The rails oi track T2 are similarly provided with insulating blocks |91, which divide track T2 into a signaling block of similar length but extending in opposite relation to the crossing.

The block associated with track TI is provided with an illustrative source of track current supply, shown as a battery TBI connected across the rails adjacent one end of the block. The circuit for battery TBI includes a current limiting resistor RI and a control switch SI. A track relay TRI is connected directly across the two rails of track TI adjacent the other end of the associated block. A similar track battery TB2 is directly connected across the rails of track T2, in series with a current limiting resistor R2 and a suitable control switch S2. A corresponding track relay TR2 is directly connected across the rails of track T2 adjacent the end of the associated block which is remote from the connection for battery TB2.

The switches SI `and S2 remain closed as long as the track system is in service and it will be appreciated accordingly that as long as no train or other vehicle, effective to shunt the track relays TR2 or TRI, occupies the track sections associated with the rela-ys, these relays are continuously energized through circuits which include the connecting rails. The energized conditions of these relays causes them to close their associated contacts TRI I and TR2 I, thus completing an energizing circuit for the coil of the crossing protective relay XR. If a train or other vehicle, efiective in accordance with conventional signaling practice to complete a shunt circuit between the two rails of either track, enters either the block associated with track TI or the block associated with track T2, part of the current otherwise supplied to the associated ftrackrelay TRI or TR2 is divertedthroughthe shunt paththusprovided, causing-such relay to fall tothe de-energized position, opening its-contact TRII or TR2I, `as the case may be. The opening of either contact TR2 I or contact TRI I interrupts the just described energizing circuit for relayXR.

`VAs soon-as the'train or other vehicle leaves the block associated'with the crossing, the relay TRE or TR2 is again energized and again aotuates the contacts TRZI orTRI I, as the case mayY be, to the closed-position,re-completing `an energizing circuit `for the crossing relay XR. .It will be seen, therefore, that the presence of a train, or-ot ier vehicle designed to operatethe barrier, Within a track section a'ssociatedwithfv either of. the two tracks TRI or TR2, causes the crossingr relay XR to fall to the de-energized position, in which it remains as long as alvehicle is in veither of the track sections associated with the crossing.

Referring lnow to Fig. 1'?, the control system -fthere shown includes a plurality otcontaets numberedrXRI, vKRE- and which are directly operated by the above described crossing relay XR. The mechanical relation betweencoil XR and contacts: XRI, XRZ and YXR is shown in rFigli. In-Fig. 17 they are shown remotely from the 'associated operating -coil in order to .simplify thev drawings.v Fig. 1T-also includes the contacts ^CI, C2, 3,05 and C5 -associated with the controller 'of drive unitY 25 (Fig 15),l as well as a .correspondingjseries ofY controller contacts CiA, 02A, CA, CtAand CEA-associated with the cony troller of-driveunit-=24A. Additional control re- Y laysMR, I-lRand DR are also shown inthe oir-- cuits, `the Vpur-pose 'andI operation of` which are described-in connection-With the description of operationof the system. The motor units are designated'dt andA MBA. It VWill be appreciated from ie ioregoingthat in -the normal conditionvofethe systerrnthat is f Awhen no-vehicle-occupies either track section as- --sociated -With thebarriersfthe relays TRL TR2 and XR-occupythe energized positions, and they are-shown in thisV relation in Figfld f Similarly, inFig. 1-7- the contacts XRl,XR2 and KRE- associated Withthe relayfXR are shown in the upper positions occupied thereb-ywhen the coil-of` the relay XR- is` energized. Y In addition, `the controller contacts CI, lC2,- etofare shown in Fig. 17

in the^positions occupiedfthereby when the associated -barriersare retracted.

With the barriers-inthe retracted positions,

the control'lercontacts Ci, 02,433 and vCta-and v CIA,C2A, CBA-and' CSA-are open. The controllercontacts C4and C4A -areclosed, but the associated circuitsarefopen atthe contacts XRl and XR?. YAccordingly, no` circuit is completed for the motorunit control relays'MR ori/[RA and the barriersremain'atrest in the retracted positions.

vAssumingthat a-vehicleenters one orrth other of "the two l track sections associated.y with the crossingof Fig.k 16, eitherrelay'TRI or-TR2 is .de-energized, correspondingly ydeenergizing the crossing relay XR.V In response to this action, the

contacts X'RI, XRZ, and -XR3 fall to positions the opposite of those illustrated in Fig. 17.

VI'his action completes the circuit for both motor relays MR and MRA, the circuit for relay MR extending from the positive line .conductor BL through contact XRI,- controllercontact ,C4 and the coilof motor relay MR to the negative line conductor BC. A similar circuit is completed for the motor relay MRA through contact XE2 and `controller contact ClIA.

Upon being energized, the two motorrela-ys MR and MRA move their associated contacts MRI and MRAI to the upper positions thereof. Contact MRE completes a circuit forv the motor unit vextending from line conductor BHI through a conventional overload device and through the motor unit armature to the negativeline conductor BC. A similar circuit is ccrnpletedfor motor unit lA. Upon completion of these circuits motor units lil and AeA Astart in rotation and initiate raising movements voi the Vassociated barriers.

When thernotor units fiiland 46A have rotated suiciently to raise the associated barriers 20 to an elevation of substantially four inches, thecontroller contacts ,Cil and CdA are actuated to the open. position, as described with reference to Fig. 12. This action interrupts thepreviously described circuits for the motor relays and- MRA, which relays fall tothe de-energized positions, releasing their contacts ,MRI and MRAI to the illustrated positions and interrupting Athe previously described circuits for the vmotor units it and 4t2-A. As previously pointed out the interruption of the motor armature circuits causes the associated brakes (not shown)v to beapplied. Relays lt/LR and MRA also complete .so-called dynamic braking circuits through theresistors itil and I 95, which are disposed to be connected directly across theassociated motor armatures,

, and assist the brakes in stopping the motors. Ac-

cordingly, the barriers associated Withtheinotor units it andilA are `each brought to rest at an elevation oi'. substantially four inches, the motor brakes acting vto hold the barriers against the lifting forces of the torsion springs.

The initial closureotthe crossing relay contactsXRS completes the circuit for Ythe time delay relay DR, which circuit extends from the positive line conductor B LL through contacts XRS, and1 Hitt, andthrough the coilDR to the negative line conductor designated BC.

The armature of relay DR isprovided with a dashpot its or other suitable delaying mechanism which delays the closure oi the contact DRI for an appreciable period after the completion of the energizing circuit for the o oil of relay D R. The time interval provided is preferably adjusted to expire several seconds after the barriers are brought to rest at the four inch points, so that the barriers remain stationary at the intermedim ate positions to provide a Warning period.

As pointed out in more detail 'in the above identiiied co-pending applications, the feature oi causing thebarriers kto remain stationary for a predetermined period at an intermediate projected position is of substantial importance. The

ymovements of the barriers to this intermediate or Warning position is sufficient to expose the Warning lettering or characters on the faces thereof, thus advising approaching traino that the barriers are about to move to their fully pro jeeted positions.V At the same time, the intermediate or warning positions of the barriers are suiliciently low .so that vehicles, which have alreadyalproached too closely to the intersection to permit astop in advance of the barriers, can pass thereover Withoutmencountering a substantial obstructing effect.

Upon the timing out ci thedashpot |99 relay contacts DRI close, completingthe circuitfor the coil of the holding relay HR, which extends from the positive line conductor BLI through the closed Contact XRB, Contact DRI, and coil HR to the negative line conductor BC. Upon completion of this circuit, relay HR closes its contacts HRI and HR2 and transfers contact HRB to the upper position. Contact HR3 completes a self-holding circuit for the coil HR and also opens the previously described energizing circuit for the coil of the time delay relay DR. Relay DR thus again resumes the cle-energized position, which action is without effect in view of the closure of the holding contact HRS.

Closure of contact HRI re-completes the circuit for the coil of the motor relay MR which circuit extends from line conductor BLI through contact XR3 and through the now closed controller contact C3 (see Fig. 11) to the coil of relay MR and thence to the negative line conductor BC. A similar circuit is completed through contact HRZ and controller contact C3A for the coil of the motor relay MRA. Upon completion of these circuits the motor relays MR. and MRA again close, placing the associated motor units 40 and MJA in operation and thereby cause the associated barriers to resume their elevating movements.

When the two motor units 40 and 40A have rotated sufficiently to permit the barriers associated therewith to reach the upper limit position thereof, or to have reached the nine and one-half inch positions indicated in the legends under Figs. 9 to 13, the controller contacts C3 and CSA, respectively, open, interrupting the previously described energizing circuits for the motor relays MR and MRA and bringing the barriers to rest at such positions, in which positions they remain until the vehicle or vehicles which initiated the starting thereof pass beyond the intersection. It will be appreciated that the length of the blocks and the rate of travel of the barriers are so related to the expected rates of travel of the traflic on the tracks TI and T2 as to effect the raising of the barriers to their fully projected positions somewhat prior to the actual arrival of the traflic at the crossing.

Assuming that the vehicle which initially deenergized the crossing relay XR passes beyond the intersection, the track relay TRI or TR2, as the case may be, again becomes energized, recompleting the energizing circuit for relay XR. On completion of this circuit, relay XR moves to the illustrated closed position, opening contact XR3 and throwing contacts XRI and XR2 to the upper positions thereof.

As described with reference to Fig. 10, the controller contacts C2 and C2A close when the associated drive units are in positions corresponding to maximum or nine and one-half inch elevations of the barriers. Accordingly, the movement of contacts XRI and XR2 to the upper positions thereof completes circuits for the motor relays MR and MRA. The circuit of motor relay MR extends from the positive line conductor BLI through contacts XRI, controller contacts C2 and through the coil of motor relay MR to the negative line conductor BC. The circuit for motor relay MRA is similar.

Upon completion of these circuits, accordingly, the motor relays lm and MRA actuate the associated motor units 40 and 40A to begin a downward or retracting movement of the barriers connected thereto. It is noted that the rotation. of the motor units M) and 4!iA continues in the same direction as in the case of the elevatingr movement. it beine noted in the previous description that the barrier elevating movements occur during approximately 180 of barrier crank shaft travel and that the barrier retracting movem-SDS occur during the remaining Q approximately of barrier crank shaft travel.

When the motor units 40 and 40A have rotated sufficiently to bring the associated barriers again to the retracted positions, the controller contacts C2 and C2A re-open, interrupting the previouslyA traced circuits for the motor relays MR and MRA, respectively, and bringing the associated barriers again to rest in the lowered positions, in which positions they remain as long as the crossing relay XR remains energized.

It may occur from time to time, where the barriers are used in connection with multiple track systems, such as shown in Fig. 16, that, after one vehicle has passed beyond an intersection and started the barrier downwardly, a vehicle will approach the crossing on one or another of the other tracks and again de-energize the crossing relay XR before the barrier has reached the fully retracted position. In accordance with the present invention, an occurrence of this kind does not interrupt the barrier movement but instead provides circuits by which the barrier is caused to continue its downward movement and immediately begin an upward movement.

Ii the barriers are moving downwardly, as described in the above paragraph, the motor relay circuits extend through contacts XRI and XRZ' and controller contacts C2 and C2A, respectively. Shortly after the downward movement is initiated and when the barriers reach the nine inch positions, the controller contacts C4 and C4A re-close, as described with reference to Fig. 12. Closure of these contacts prepares circuits for the motor relays MR and MRA, which circuits are, however. open at the contacts XRI and XRZ. Assuming now that a second train approaches the intersection and again de-energizes relay XR, the motor relay circuits previously completed through the controller contacts C2 and CZA are interrupted at contacts XRI and XR2. The dropping of these contacts to the illustrated positions, however, re-completes motor relay circuits through the controller contacts C4 and CdA, so that the barrier movement is not interrupted by the approach of the second train. Since contacts C4 and C4A remain closed until the barriers have passed the retracted position and again risen to the four inch position, it will be appreciated that the barrier movements will not be stopped when the retracted positions are reached thereby. The remainder of the operating cycle is as previously described, except the period of rest at the four inch point is necessarily shortened an amount equal to the time required for the barrier to nish the already started lowering movement. Thus, the barrier will reach the re-elevated position just as promptly as though the barrier had been in the fully retracted position at the time such second train entered the block.

It may also occur from time to time, through one cause or another, that one of the track relays TRI and TR2 will be temporarily de-energized, the period of de-energization being too short to give the barriers time to rise to the fully elevated position. This may occur, for example, when a train or vehicle moves into a section a short distance and then retires therefrom. In accordance with the present invention, however, the arrangement is such that even such a momentary deenergization of the track relay is effective to cause both barriers to move to the fully projected positions and then return to the retracted positions.

Assuming for example that relay XR is temporarily cle-energized, the de-energization thereassume the illustratedpositions, ,which action, as previouslyv` described, starts both motor units 40 and 48A into operation. After a slightv amount of barrier movement of the order for example of one-half inch,1the controller contacts C5 and CEA close (see Fig. '13) and form .parallel shunt circuits around the crossing relay contact XRS.

The just stated shunt action is obtained, therefore, even though only one of the barriers rises tothe height required to cause closure of the contactsY C5 or CEA. After closure of either of contacts CSorCiiA, it will be, appreciated that a re-opening,of contact, XR3 is Without effect upon the system. The just .mentioned slight ,initial movements of the barriers also cause clovsure of .the controller .contacts CI and CIA. After. the closure of these contacts, a transfer of the relay contactsr XR! and XRZ to the upper positions thereof resulting from the re-energization of relay XR is withouteffect upon the system. Contacts :CI and CIA re-open at the four inch,z level-of the barriers in order to give the usual hesitation to the .barrier movement, the

vremaining.upwardmovernent of the barriers beingifeiected vthrough `the contacts Cand CSA,

as described with reference to therst sequence of operation. 'The contacts C5 and rCEA reopen at the barrier nine and one-half inch points Without effect, since thethen closed contacts C2 andC2A1effect the returnxmovements to the retracted positions.

i It Will be noted fromfFig.`.17. that y'two sepfarately; identified positive line conductors" BL! yaInitBHI are indicated. This is for the reason that it is` preferred to provide a higher voltage source ofpowerifor operating-themotor units '40- andf 43A than for operating the relays asso- ;ciatedywith the motor units.

current supply system. A transformer TI is connected across the line conductors Li Iand 'L2 and; through a conventional rectifier CI, delivers `direct current of a voltage suitable for operating l,the motorunits dii and: @Ato `the line conductor BH I and the common return line BC, eX-

tensions of which conductors are shown and correspondingly designated in Fig. 17. A similar ransformer T2 is connected across ,the line conductors LI and L2 and, through a similar conventional rectifier C2, delivers direct current of a voltage suitable for operating the relays described with reference to Fig. 17 to the line ccnductor BL! and to the common return line BC.

In order to insure the provision of an adequate power supply for operating both the motor units and the relay mechanism, even in the event of failure of the just described alternating current supply system, two batteries, designated as SBI and SBZ, are preferably provided. The two terminals of battery SBZ, constructed to deliver a voltage corresponding to that of transformer T2, are connected directly across the line conductcrs BL! and BC. The two batteries SBI and SB2 are interconnected, in additive relation, and the free terminal of battery SBI is connected to the line conductor BHI. Batteries SBI and SBZ, in. series, are constructed to deliver a voltage substantially equal to the secondary voltage of transformer TI. A third transformer T3, intended primarily to supply alternating current for lighting warning signals and other signals preferably provided in connection With the bar- Vriers, is connected across the line conductors LI ,and L2." The secondary thereof` directly supplies the coil of a. transfer relay'LR. As long as the line conductors L! and L2 remain energized, relay LR remains energized and holds contacts LR! and LRE in the upper positions, in which positions the line conductors XL! and XL2 are directly supplied with alternating current through transformer T3. In the event of failure of the alternating current source or failv ureof transformer T3, the contacts ofthe relay LB drop, connecting the conductors XLI and XL2 directly across the low voltage direct current lines BL! and BC, thus supplying the lighting circuits from the direct current source.

Although a: speciic embodiment ofthe present invention has been described, it will be apprcciated that various changes in the structure and arrangement may be made within the spirit and scope thereof.

-What I claim is:

1. In a control system for a protective device embodying a retractable and projectable barrier provided with a motor operatively connected to saidbarrier and effective through unidirectional operation to project and retract said barrier, a circuit for said motor, a controller for said motor leffective to complete said circuit to cause said motor to start in operation and actuate said barrier to a projected position, and to thereafter recomplete said circuit to causesaid motor to actuate` said barrier to a retracted position, and means includingY timing mechanism for interrupting said circuit for a predetermined interval during said projecting movement.

2. In a controlsystem for a protective device embodying abarrier adapted to assume projected and retracted positions and provided Vwith a motor 'for actuating it between said positions, relay mechanism and means responsive thereto eifective upon operation to cause said motor means to start and actuate said barrier to a projected-position, means including timing mechanism responsive to said relay mechanism for stopping said motor for a predetermined interval at an intermediate stage of said projecting movement, means associated with said motor effective vupon rie-operation of said relay mechanism for causing said motor to actuate said barrier to the retracted position, said first mentioned means being responsive to a re-operation of said relay mechanism during a retracting movement of saidbarrier for continuing said barrier movement tothe retracted position.

3. In a'control system for a protective device embodying a barrier adapted to assume projected and retracted positions and provided with a unidirectionally operable motor for actuating it between said positions, a circuit for said motor, relay mechanism effective upon operation to cause completion of said circuit to thereby cause motor to project said barrier, means including timing mechanism responsive to said relay mechanism for stopping said motor for a predetermined interval at an intermediate stage of said projecting movement, and additional means responsive to de-operation of said relay mechanism to cause completion of said circuit to thereby cause a retracting movement of said barrier.

4. In a control system for a protective device embodying a barrier adapted to assume projected and retracted positions and provided with a motor for actuating it between said positions, relay mechanism and means responsive thereto effective upon operation to cause said motor means to start and actuate said barrier to a projected position, means including timing mechanism responsive to said relay mechanism for stopping said motor for a predetermined interval at an intermediate stage of said projecting movement, means associated with said motoreiiective upon cie-operation of said relay mechanism for causing said motor to actuate said barrier to a retracted position, said first mentioned means being responsive to a re-operation of said relay mechanism during a retract-ing movement of said barrier for continuing said barrier movement to the retracted position and for causing said motor to remain in operation and actuate said barrier to the projected position.

5. In a control system for a protective device embodying a barrier adapted to assume projected and retracted positions and provided with a motor for actuating it between such positio-ns, relay mechanism for placing said motor in operation to thereby initiate a projecting movement of said barrier, a controller for said motor controlled in accordance with the position of said barrier and including means for maintaining said motor in operation independently of the condition of said rela-y mechanism, and means including timing mechanism responsive to said relay mechanism for stopping said motor for a predetermined interval at an intermediate stage of said projecting movement and for restarting said motor at the end of said interval.

6. In a control system for a protective device embodying a barrier adapted to assume projected and retracted positions and provided with means including a motor for actuating it between said positions, relay mechanism for placing said motor in operation to initiate a projecting movement of said barrier, a controller for said motor actuated in accordance with barrier movement and effective after said barrier has reached a predetermined elevation to continue said motor in operation independently of the condition of said relay mechanism, and means including timing mechanism responsive to said relay mechanisrn for stopping said motor for a predetermined interval at an intermediate stage of said projecting movement and for restarting said motor at the end of said interval.

7. In a control system for a protective device embodying a retractable and projectable member provided with a motor operatively connected to said member and effective through unidirectional operation to project and retract said member, the combination of an operating circuit for said motor, means operable to cause completion of said circuit so that said motor starts to move said member from said retracted to said projected position, additional means operable to cause completion ci said circuit so that said motor starts to move said barrier from said projected to said retracted position, and timing mechanism associated with said first means for causing an interruption of said operating circuit for a predetermined interval during said projecting movement.

8. In a control system for a protective device embodying a retractable and projectable member provided with a motor operatively connected thereto and effective through unidirectional operation to project and retract said member, the combination of an operating circuit for said motor, relay mechanism operable to cause completion oi said operating circuit so that said motor starts said member from said retracted to said projected position, a controller operable in accordance with the movement of said motor for interrupting said operating circuit at an intermediate point in said movement, timing mechanism associated with said motor for causing recompletion of said circuit so as to continue said movement of said member, and additional mechanism operable to cause completion of said operating circuit so that said motor moves said member from said projected to said retracted position.

9. In a control system for a protective device embodying a retractable and projectable member provided with a motor operatively connected thereto and eiective through unidirectional operation to project and retract said member, an operating circuit for said motor, relay mechanism operable between first and second positions, a controller for said motor controlled in accordance with the position thereof and having means responsive to an operation of said relay mechanism to said iirst position for causing closure of said operating circuit to cause said motor to start said member in a projecting direction, timing .echanisrn associated with said controller for interrupting said operating circuit at an intermediate point in said projecting movement and for causing reccmpletion thereof at the expiration of a predetermined interval, and additional means forming part of said controller and responsive to an operation of said relay mechanism 'to said second position for causing closure of said operating circuit to cause said motor to move said member from said projected to said retracted position.

JAMES MOORE EVANS. 

